Safety flap-valve

ABSTRACT

A straightway safety flap-valve to be mounted on a tube conveying a pressure fluid and comprising: a collar secured to one open end of said tube and provided with a valve seat; a clack pivoted to said collar about a first axis extending outside of the surface of said tube and rotatable through 90* for engagement with and disengagement from said seat; a yoke pivoted to said collar about a second axis parallel to the first one and intersecting the surface of said tube; a third axis passing through the free ends of said yoke in parallel relation to the two first axes and also extending through said clack adjacent to its first pivot axis; control means for rocking the yoke about said second axis and acting on the closed end of said yoke; and a vertically slidable counterweight surrounding at least partially said tube end and supported through links pivoted to said counterweight and to the free ends of said yoke adjacent to said third axis.

United States Patent 1191 Colonna Jan. 29, 1974 SAFETY FLAP-VALVEPrimary Examiner-Arnold Rosenthal Attorney, Agent, or Firm-Kenyon &Kenyon Reilly [75] Inventor: Jean Colonna, Joinville-Le-Pont, & p

France [73] Assignee: Gaz De France, Paris, France [57] ABSTRACT Astraightway safety flap-valve to be mounted on a Flledi p 1972 tubeconveying a pressure fluid and comprising: a collar secured to one 0 enend of said tube and rovided 21 A l. N 289546 p 1 pp 0 with a valveseat; a clack pivoted to said collar about a first axis extendingoutside of the surface of said Forelgn pp y Data tube and rotatablethrough 90 for engagement with Sept. 21, 1971 France 7133970 anddisengagement from said seat; a yoke pivoted to said collar about asecond axis parallel to the first one [52] US. Cl 251/58, 251/147,251/303 and intersecting the surface of said tube; a third axis [51]Int. Cl. Fl6k 31/163 passing through the free ends of said yoke inparallel [58] Field of Search 25 1/299, 303, 58, 147 relation to the twofirst axes and also extending through said clack adjacent to its firstpivot axis; control means for rocking the yoke about said second axisReferences Cited and acting on the closed end of said yoke; and a verti-UNITED STATES PATENTS cally slidable counterweight surrounding at leastpar- 1,783,621 12/1930 Johnson 251/147 x tially Said tube end andSupported through links P 3,075,s39 1/1963 Yoder 251/299 x oted to saidunte ight and t the free nds of said 3,442,484 5/1969 Carr et a1.251/147 X yoke adjacent to said third axis.

' 10 Claims, 11 Drawing Figures I L I '9 O 3 110 PATENTH] JAN 29 I574SHEET 3 [IF 4 i 'iiki rl/1113147 PATENTED JAN 2 91974 SHEET u 0F 4 1SAFETY FLAP-VALVE The present invention, relates essentially to a safetystraight-way flap-valve or clack-valve or like hanging valve adapted tobe mounted on a pipe-line or duct or on a tube through which a pressurefluid is flowing. The valves designed according to the present inventionare adapted in particular to fit heads of wells producing combustiblegases such as natural gases; their use may also be contemplated in oilproducing wells.

The safety valves known heretofore are not entirely satisfactory eitherbecause they do not allow direct passage of the fluids or because theyare of a too complicated structure and of a too expensive manufacture.

The known safety valves. allowing to fully clear the cross-sectionalarea of the fluid passageway are indeed of a very costly and complicatedconstruction. Under such circumstances one often is reluctant to usesame. The use of simpler valves however wherein the fluid passage is notdirect or straightway exhibits many inconveniences. In particular itbecomes impossible or at least very difficult to have a tool being movedinto the tube thereby limiting the working or producing capabilities.

The invention relates to a safety straightway flapvalve of a simple andnot very expensive design and construction, having a very small size orbulk and the operation of which is perfectly reliable. For this purposeit comprises, mounted, for instance screw threaded, on an open end ofsaid tube, a collar provided with a valve seat, a clack or likeflap-valve member pivotally mounted on said collar about a first axislocated outside of the surface of said tube so as to be movable to closethe open end of said tube by bearing upon said seat in the closingposition of the valve and to completely clear the open end'of the tubeafter a rotation of about 90 of said clack about the first axis, a

yoke or like clevis pivotally mounted on said collar about a second axisparallel to the first-one and intersecting the surface of said tube, athird axis passing through the free ends of said yoke in parallelrelation to the two first axes and also extending through said clackadjacent to its first aforesaid pivot axis, control means for rocking,tiltingor tipping the yoke about said second axis which act upon theclosed yoke end opposite to those through which said third axis extends,and a counterweight mounted for vertical sliding motion and surroundingat least partially said end portion of the tube, said counterweightbeing supported through links pivoted to said counterweight and to thefree ends of said yoke adjacent to said third axis.

With such a design of embodiment is achieved a valve of compactconstruction the closing of which may be very easily controlled forexample by a hydraulic actuator of low power or output.

The invention will appear more clearly as the following descriptionproceeds with reference to the accompanying drawings given by way ofexample only illustrating a form of embodiment of a flap-valve designedaccording to the invention.

In these drawings FIG. 1 shows in cross-section with parts broken away ageneral assembly view of a valve designed according to the invention andmounted at the end of a tube FIG. 2 is an exploded perspective viewdrawn at a smaller scale and showing the main parts composing thestructure of the valve shown in FIG. 1

FIG. 3 shows at a larger scale and in longitudinal cross-section theessential parts of the valve illustrated in FIG. 1 and correspondingsubstantially to the central portion of this Figure FIG. 4 is a view inhorizontal section taken substantially upon the line lV-IV of FIG. 3

FIG. 5 is a sectional view of a detail, this view being taken upon theline V-V of FIG. 4

FIG. 6 shows a clack-disk dsigned according to a modification FIG. 7 isa view in section taken upon the line VI]- VII of FIG. 6 andillustrating a detail of this Figure FIGS. 8, 9 and 10 show analternative form of embodiment of the clack and of its operating meansfor open same and FIG. 11 is an exploded perspective view showing somestructural details of FIGS. 8 to 10.

Referring first to FIGS. 1 to 5, a flap-valve 10 designed according tothe invention is mounted at the free end of a tube, pipe or duct 11 forthe passage or conveyance of the fluid. This tube or pipe may be forexample one of the elements of a drill pipe string for the head of awellproducing a natural gas. The involved end of tube 11 may be located forinstance under the surface of the ground at a depth of the order of 30m. The valve assembly l0 is mounted within a casing or housing 12 whichis mounted, for example screw threaded at 13 by means of a fittingconnector 91 onto the free end l l'a of pipe 11'. The casing 12 has anextension. in the shape of a frusto-conical portion 14 which connectswith or merges into a tubular portion 15 substantially in extension'of atubular element or tube 11 which is in extension of the pipe 1 l. Thetubular element 11 is secured, for instance screw threaded at 90 ontothe coupling or fitting 91 connecting the valve with the pipe 11 At thefree end of the portion 15 will be connected another tube (not shown)that will be located in extension of the tubes 11 and 11 and will have asimilar diameter. Desirably for ease of mounting, that portion of tube11 about which the valve 10 is mounted is screw threaded at both of itsends. This facilitates the connection with the tube 11' and the mountingof the collar 16 which carries the pivot mechanism of the clack orflap-valve member 17.

The valve essentially comprises the collar 16 made fast at the loweropen end 11a of tube 11 for instance through screw threading this collar16 comprises as seen on FIG. 3 a desirably spherical seat 18 cooperatingwith the working or bearing surface of the closure disk 19 of the clackl7 the working surface 20 of disk 19 bearing onto the seat 18 is also ofspherical shape the clack 17 which consists of the closure disk 19 andof a holder 21 for this disk having a surface 22 for fastening the diskand a pair of lugs 23 extending at right angles to the surface 22, saidlugs being provided each one with two bores 24, 25 the clack 17 ispivoted about a first axis materialized by a pivot pin 26 which extendsthrough the bores 25 of lugs 23 and through a bore 28 formed in a lug 29of the collar 16 a yoke or clevis 30 formed from a flat sectional stripbent in U- shape and pivotally mounted on the collar 16 about a secondaxis materialized by bolts 31 screw threaded into the collar 16 andextending through the bores 32 formed in the central portion of the lugs33, 34 of the yoke 30; notches 35 formed in each one of the free ends oflugs 33, 34 of the yoke 30 and which receive each one a loose roller 36mounted for free rotation about a pivot pin 37 which extends through thebores 24 provided in the lugs 23 of the clack holder a counterweight 40mounted for vertical sliding motion and encompassing for a major partthe portion of tube 11, said counterweight being supported through themedium of links or connecting rods 41 pivoted onto said counterweightand onto the free ends of the yoke 30 the links 41 are pivotallyconnected onto the counterweight through pivot pins 43 and onto the yoke30 by pins 44 which extend through the bores 46 of the yoke thecounterweight 40 comprises moreover guide rollers 45 in its upperportion operating means for rocking or tilting the yoke 30 about theaxis of pivots 31 (second aforesaid axis) and acting upon the base ofthe U of the yoke 30 to this end the yoke 30 is formed with a tab 47upon which is acting the end 48 of an operating actuator 49 the end 48comprises a pair of rollers 79 mounted on a fork 50 secured to a rod 51integral or rigidly connected with the piston 52 of the actuator 49 thecylinder 53 of which is connected to a duct 54 for pressurizing forexample with oil.

In addition to these essential parts the valve comprises accessorydevices or like attachments. Thus as seen more clearly in FIGS. 4 andthere is provided a pressure equalizing or balancing device 56 whichcomprises a valve 57 mounted on a resilient blade or strip 58 adapted toclose an aperture 59 provided in the wall of tube 11. In the normalworking position, the biasing blade 58 keeps the valve 57 applied orurged within the aperture 59 against the outer wall of tube 11.

In the closure disk 19 of the clack there is provided a recess or likehousing 60'with a substantially frustoconical portion which terminatesin a hole 61 opening inwards of tube 11 (in the closing position of theclack). Holes 62 for example three in number are provided in the surface22 supporting the disk 19 and communicate with the recess 60. Moreoverwithin the recess 60 is mounted a ball 63 which is captive or retainedand the diameter of which enables to close the orifice 61.

In an alternative form of embodiment illustrated on FIGS. 6 and 7, theclosure disk 19 of the clack is mounted on the disk supporting surface22 for example by means of a screw 65 while leaving some clearancebetween the surface 22 and .the disk 19. Resilient means such as springsfor instance or resilient washers diagrammatically shown by the dashes66 may be fitted between the disk 19 and its carrier 22. In this manneran outstanding bearing engagement of the disk 19 with its seat in theclosing position of the clack is achieved.

The safety straightway flap-valve described opeates in the followingmanner. In the normal working position a fluid pressure maintained inthe chamber 53 of the operating actuator 49 of the valve keeps the clackl7 positively in the open position as shown in solid lines on FIG. 3. Inthis position it is seen that the end 11a of tube 11 is entirely clearedor freed so that it is possible to run any tool whatever through thepipe string 11 without being hindered by the mounting of the flapvalve.

If the pressure happens to decrease or to lack within the chamber 53 ofthe actuator, the counterweight 40 pushes through the medium of thepivotally connected links 41 the pin 44 downwards thereby urging theyoke 30 to swing about the pivots 31 in the direction of the arrow Fthereby causing simultaneously, through the notches 35 wherein therollers 36 are riding, the clack 17 to swing about its pivot pin 26until the closing of the clack as shown in dash-dotted lines in FIG. 3.

If the internal leakage flow rate that flows through the clack whilepassing through the orifices 62, the recess 60 and the orifice 61,remains low enough, the pressure differential between either side of theclack is not very significant and it is usually possible to re-open samethrough a simple action of the actuator 49 when the control pressurewithin the cylinder 53 of the actuator is brought back to a normaloperating value.

When on the contrary the internal leakage flow rate reaches a previouslydetermined limiting value, the ball 63 is pressed against the opening 61and the effective pressure under the clack may become very large. Undersuch circumstances it is not usually possible to re-open the clackthrough mere action of the actuator 49 the operating rod 51 and fork 48of which are not powerful enough. When it is desired to re-open thevalve it would be sufficient to operate the pressure equalizing orbalancing device 56 previously described. To do this it would besufficient to move a tool into and down the tube 11 to push that portionof the valve 57 which projects into the tube 11. The fluid pressureunder the clack may thus be equalized or balanced on either side of theclack by flowing through the bore 59. When the pressures aresubstantially equalized or balanced it will then be possible to operatethe actuator 49 to re-open the clack.

The nature of the materials forming part of the composition-of the valvewill of course be selected so as to withstand the operating conditionsor working requirements of the valve that is essentially the physicaland chemical conditions to which it will be subjected inside of thefluid which circulates within the tube 11.

According to the alternative form of embodiment shown on FIGS. 8 to 11,wherein like parts which are shown in the preceding Figures have beendenoted by the same reference numerals whereas similar parts but ofdiffering configuration have been designated by the same referencenumerals increased by hundred units, there is provided, under theclack-hodling surface 122, a lever 70 pivoted about a pivot pin 71 whichextends through the bores 72 of lever 70 and 73 of the clackholder 122,respectively. The lever 70 comprises a needle or conical pin 74 whichunder the action of a spring 75 made fast with the lever 70 and bearingunder the clack-holder 122 is caused to normally close an opening 76provided in the clack 117. I The lever is moreover so shaped that thefork 50 of the opening arrangement for' opening the clack is caused tobear with its end 50a against the end 70a of lever 70 at the beginningof the opening of the clack (FIGS. 8 and 9). Under these circumstancesat the beginning of the opening when the piston 52 tends to lower thefork 50, the end 50a of the latter is caused to engage the end 70a oflever 70 thereby swinging the latter about its pivot pin 71 before theroller 79 has acted upon the tab 47 of the yoke 30. In acting so, theopening 76 is cleared by the needle or conical pin 74 whereby anautomatical equalizing or balance of the pressures on either side of theclack 117 is achieved before the opening operation proper.

When the pressure equalizing is substantially obtained, the piston 52continuing its stroke operates the yoke 30 through the roller 79 of thefork 50 as previously described thereby resulting in the opening of theclack 117.

At 80 is shown a spring leaf which acting upon spigots 81 or likeprojections of the fork 50 moves or urges this latter back to the upperposition (FlG. 8) when the operating pressure in the actuator 49 issmall.

In a form of embodiment contemplated the tube 11 having an innerdiameter of 60 mm a valve of the kind described has been designed tomeet or comply with the following requirements 1 Automatic closurethrough exhaust or venting to the atmosphere of the end of the controlline 54, i.e. the valve being generally located at 30 m below groundlevel, when the pressure in the actuating cylinder 53 decreases to aneffective value of about 2.5 bar..

2 Balance, with the clack closed, of the upstream and downstreampressures by means of the flow rate limiting device having-a ballincorporated into the clack and allowing a limit flow rate of 50 Nm /hunder a pressure of 150 bar.

3 Opening pressure of between 60 and 80 bar at the head end of the line54 after pressure equalization thus a good disengagement of the clackfrom its seat or initial motion of the clack off its seat is obtained.

4 An internal leakage fl'ow rate of 5 Nm /h under a pressuredifferential of 100 bar after closing of the limiting ball device.

5 A maximum working pressure of 150 bar.

It should be understood that the invention is not at all limited to theforms of embodiment described and shown which have been given by way ofexample only. In particular the invention may apply to many fields ofuse every time it is desired to obtain an automatic closing of a tube,duct or like pipe-line while retaining a straightway of direct passageof the fluid, each time abnormal operating conditions occur in use. Theinvention therefore comprises all the technical equivalents to the meansdescribed as well as their combinations if same are carried out inaccordance with its gist and are put into practice within the scope ofthe appended claims.

What is claimed is:

l. A safety straightway flap-valve adapted to be mounted on a tubeconveying a pressure fluid comprising, mounted on the open end of saidtube a collar provided with a valve seat a clack pivoted to said collarfor swinging about a first axis located outside of the surface of saidtube so as to be able to close the open end of said pipe when bearingagainst said seat in the closing position of the valve and to fullyclear the open end of said tube after a rotation of about 90 of saidclack about said first axis a yoke pivoted to said collar for rockingabout a second axis coextensive in parallel relationship with the firstone and intersecting the surface of said tube a third axis passingthrough the free ends of said yoke in parallel relation to the two firstaxes and also extending through said clack adjacent to its first pivotaxis control means for tilting said yoke about said second axis andacting upon the closed end of said yoke which is opposite to thosethrough which said third axis extends and a counterweight mounted forvertical sliding motion and surrounding at least in part said end ofsaid tube, said counterweight being supported through links pivotallyconnected to said counterweight and to the free ends of said yoke,respectively, adjacent to said third axis.

2. A valve according to claim 1, wherein said clack comprises a closuredisk of a shape conforming to that of said valve seat and a holder forsaid disk comprising a disk fastening surface and a pair of parallellugs extending at right angles to'said surface, said lugs being providedeach one with two mutually confronting bores for the passage of pivotpins materializing said first and third axes.

3. A valve according to claim 2, wherein said yoke is made from a bentU-shaped sectional flat strip and is mounted on said collar by means ofa pair of pins extending substantially through the centres of each lugof said U-shaped yoke thereby materializing said second axis and thereis provided a notch in each one of the free ends of said sectional yoke,which notches receive each one a loose roller mounted for free rotationabout a pivot pin materializing said third axis and extending throughtwo of said mutually confronting bores formed in said lugs of said clackfor operating the rotation of the clack about its first axis.

4. A valve according to claim 1, wherein said tube is directedvertically, said collar is secured to the bottom end of said tube, saidclack being located below said yoke and the latter being located belowsaid counterweight said first and second axes for pivotal connectionwith said collar of said clack and said yoke being substantially on asame level; said first axis extending 7 outside of said tube and saidsecond axis passing substantially through a centre plane of said tube.

5. A valve according to claim 3, wherein the operating means for rockingsaid yoke comprise a hydraulic actuator which acts upon the base of theU-shaped yoke in a direction substantially parallel with the axis ofsaid tube adjacent to the portion involved.

6. A valve according to claim 2, wherein there is provided in saidclosure disk of said clack a substantially frusto-conical recess with ahole opening towards the inside of said tube and a plurality of holes inthe disk fastening surface providing an internal leakage flow throughsaid clack as well as a ball mounted in said frusto-conical recess andcaptive between said disk and its fastening surface, said ball beingadapted to close the hole formed through said disk when the leakagethrough said clack becomes too large.

7. A valve according to claim 2, wherein said disk is mounted withclearance onto said fastening surface.

8. A valve according to claim 1, wherein there is provided, in said tubedownstream of said clack with respect to the stream of fluid flowingthrough the tube, an opening which is closed by a valve member which iskept applied by resilient means against the outer wall of said tube,said valve member projecting slightly into said tube so that it may bemoved mechanically off its seat by running a suitable tool through saidtube.

9. A valve according to claim 1, wherein the assembly of the partscomposing said valve is mounted within a casing which is mounted in turnso as to encompass said tube near the free end thereof and said casingis formed with a frusto-conical extension connecting with a tubularportion substantially in extension of said free end of said tube.

10. A valve according to claim 2, wherein said closure disk of saidclack is formed with an orifice and there is provided a lever pivotedunder said disk about a pivot pin extending in parallel relation to saidthree axes and carrying a needle which closes said orifice in theposition of said lever applied against said disk, resilient means beingprovided to normally press said lever against said disk and saidoperating means for tilting said yoke being adapted to swing said leveraway from said closure disk before bearing against said yoke so as tocause the rocking of the clack and to operate the opening thereof.

1. A safety straightway flap-valve adapted to be mounted on a tubeconveying a pressure fluid comprising, mounted on the open end of saidtube : a collar provided with a valve seat ; a clack pivoted to saidcollar for swinging about a first axis located outside of the surface ofsaid tube so as to be able to close the open end of said pipe whenbearing against said seat in the closing position of the valve and tofully clear the open end of said tube after a rotation of about 90* ofsaid clack about said first axis ; a yoke pivoted to said collar forrocking about a second axis coextensive in parallel relationship withthe first one and intersecting the surface of said tube ; a third axispassing through the free ends of said yoke in parallel relation to thetwo first axes and also extending through said clack adjacent to itsfirst pivot axis ; control means for tilting said yoke about said secondaxis and acting upon the closed end of said yoke which is opposite tothose through which said third axis extends ; and a counterweightmounted for vertical sliding motion and surrounding at least in partsaid end of said tube, said counterweight being supported through linkspivotally connected to said counterweight and to the free ends of saidyoke, respectively, adjacent to said third axis.
 2. A valve according toclaim 1, wherein said clack comprises a closure disk of a shapeconforming to that of said valve seat and a holder for said diskcomprising a disk fastening surface and a pair of parallel lugsextending at right angles to said surface, said lugs being provided eachone with two mutually confronting bores for the passage of pivot pinsmaterializing said first and third axes.
 3. A valve according to claim2, wherein said yoke is made from a bent U-shaped sectional flat stripand is mounted on said collar by means of a pair of pins extendingsubstantially through the centres of each lug of said U-shaped yokethereby materializing said second axis and there is provided a notch ineach one of the free ends of said sectional yoke, which notches receiveeach one a loose roller mounted for free rotation about a pivot pinmaterializing said third axis and extending through two of said mutuallyconfronting bores formed in said lugs of said clack for operating therotation of the clack about its first axis.
 4. A valve according toclaim 1, wherein said tube is directed vertically, said collar issecured to the bottom end of said tUbe, said clack being located belowsaid yoke and the latter being located below said counterweight ; saidfirst and second axes for pivotal connection with said collar of saidclack and said yoke being substantially on a same level ; said firstaxis extending outside of said tube and said second axis passingsubstantially through a centre plane of said tube.
 5. A valve accordingto claim 3, wherein the operating means for rocking said yoke comprise ahydraulic actuator which acts upon the base of the U-shaped yoke in adirection substantially parallel with the axis of said tube adjacent tothe portion involved.
 6. A valve according to claim 2, wherein there isprovided in said closure disk of said clack a substantiallyfrusto-conical recess with a hole opening towards the inside of saidtube and a plurality of holes in the disk fastening surface providing aninternal leakage flow through said clack as well as a ball mounted insaid frusto-conical recess and captive between said disk and itsfastening surface, said ball being adapted to close the hole formedthrough said disk when the leakage through said clack becomes too large.7. A valve according to claim 2, wherein said disk is mounted withclearance onto said fastening surface.
 8. A valve according to claim 1,wherein there is provided, in said tube downstream of said clack withrespect to the stream of fluid flowing through the tube, an openingwhich is closed by a valve member which is kept applied by resilientmeans against the outer wall of said tube, said valve member projectingslightly into said tube so that it may be moved mechanically off itsseat by running a suitable tool through said tube.
 9. A valve accordingto claim 1, wherein the assembly of the parts composing said valve ismounted within a casing which is mounted in turn so as to encompass saidtube near the free end thereof and said casing is formed with afrusto-conical extension connecting with a tubular portion substantiallyin extension of said free end of said tube.
 10. A valve according toclaim 2, wherein said closure disk of said clack is formed with anorifice and there is provided a lever pivoted under said disk about apivot pin extending in parallel relation to said three axes and carryinga needle which closes said orifice in the position of said lever appliedagainst said disk, resilient means being provided to normally press saidlever against said disk and said operating means for tilting said yokebeing adapted to swing said lever away from said closure disk beforebearing against said yoke so as to cause the rocking of the clack and tooperate the opening thereof.